Anterior cruciate ligament reconstruction: the diagnostic value of MRI

A prospective study was carried out in order to evaluate the predictive val ue of MRI in the early postoperative course after cruciate ligament replace ment. Twenty patients who had undergone anterior cruciate ligament reconstr uction using autologous patellar tendon/bone grafts were examined clinicall y and with contrast enhanced MRI at 2, 12 and 24 weeks, and 1 and 2 years a fter operation. The clinical findings were evaluated according to the score s established by Lysholm, OAK and IKDC. The MRI scans (SP 63, 1.5 Tesla) we re assessed in terms of the quality and signal intensity of the reconstruct ed ligaments. During the first postoperative year there was a significant i ncrease of signal intensity and in homogeneity of the neoligament on in the MRI. Seventeen patients had an average value for signal/noise of 1.1 at tw o weeks after surgery, which had increased to 7.1 at 1 year. In 14 patients the reconstructed ligament could not be evaluated in MRI scans after 1 yea r but clinical instability was not suspected in any of these patients. Two years after operation the MRI signal intensity of the neoligament was again decreasing.